1. Field of the Invention
The present invention relates to an inkjet recording device, and more specifically to a high-speed inkjet recording device that reliably prints high quality images
2. Related Art
Line-scan inkjet printers are a type of high-speed inkjet printer capable of printing on a continuous recording sheet at high speeds, and include an elongated inkjet recording head formed with rows of nozzles for ejecting ink droplets. The head is arranged in confrontation with the surface of the recording sheet across the entire width of the recording sheet. The head selectively ejects ink droplets from the nozzles based on a recording signal and impinges the droplets on desired positions across the width of the recording sheet. At the same time, the recording sheet is transported rapidly in its lengthwise direction, which serves as a main scanning operation so that images can be recorded at any place on the recording sheet.
Various types of line-scan inkjet printers have been proposed, such as printers that use a continuous inkjet type recording head and printers that use a dot-on-demand type recording head. Although dot-on-demand type line-scan inkjet printers have a slower printing speed than do continuous inkjet type line-scan inkjet printers, they have an extremely simple ink system and so are well suited for a general-purpose high-speed printer.
The recording head used in dot-on-demand type line-scan inkjet printers includes rows of nozzles, ink chambers in fluid communication with the nozzles, and piezoelectric elements or thermal elements for each ink chamber. The piezoelectric elements or thermal elements are driven to apply pressure to the ink in the ink chambers. The increase in pressure ejects an ink droplet from the corresponding nozzle in one dot-on-demand type line-scan inkjet printer, charging/deflecting electrodes are provided following the row of nozzles for deflecting ink droplets so that ink droplets ejected from adjacent nozzles impinge on the same pixel position. Because the impinging target of adjacent nozzles can be overlapped in this way, a complete image without missing information will be recorded even if some nozzles become defective and so cannot properly eject ink. This increases reliability of the printer and improves consistency in recording.
Japanese Patent Application No. 2001-47622 discloses a method for improving the yield of line-type recording head that includes charging/deflecting electrodes. In this method, short recording head modules with deflecting electrodes to the side of the nozzles are aligned end to end on a mounter to a length that matches the width of the recording sheet
However, this conventional configuration requires a large number of charging/deflecting electrodes and a mounter, so that a great number of components need to be provided. Also, the components need to be assembled with the electrodes positioned precisely with respect to the nozzles. Further, the recording head needs to be positioned precisely on the mounter. Overall, the production costs of the head are high.
Further, because the electrodes located near nozzles protrude slightly from a nozzle surface in which the nozzles is are formed, a proper seal cannot be achieved around the nozzle holes by, for example, a capping mechanism or an ink purge mechanism provided for preventing the nozzles from being clogged.
Moreover, when the recording sheet lifts up toward the recording head or jams, the recoding sheet can scrape across and damage the nozzle surface.
In view of forgoing, it is an object of the present invention to overcome the above problems and also to provide an inkjet recording device with charging/deflecting electrodes that can be manufactured with low costs.
In order to achieve that above and other objects, the present invention provides a recording head including a plurality of head modules each formed with a plurality of nozzles, and an electrode assembly including assembled charging/deflecting electrodes for the plurality of head modules. The plurality of recording modules are attached to the electrode assembly. The electrode assembly serves as a mounting member for mounting all of the plurality of head modules thereon.
There is also provided an inkjet recording device including a recording head and a capping means. The recording head includes a plurality of head modules each formed with a plurality of nozzles, and an electrode assembly including assembled charging/deflecting electrodes for the plurality of head modules. The plurality of recording modules are attached to the electrode assembly. The electrode assembly serves as a mounting member for mounting all of the plurality of head modules thereon, and includes a conductive electrode plate formed with windows corresponding to the plurality of head modules. The head module includes a corresponding nozzle plate formed with the plurality of nozzles defining a nozzle row. The conductive electrode plate is in intimate contact with the nozzle plate. The nozzle row extends following one edge of the corresponding window. The capping means is in intimate contact with a side of the electrode plate that is opposite from a side of the electrode plate to which the nozzle plate is attached so as to block off the windows.
There is further provided an inkjet recording device including a recording head and purging means. The recording head includes a plurality of head modules each formed with a plurality of nozzles, and an electrode assembly including assembled charging/deflecting electrodes for the plurality of head modules. The plurality of recording modules are attached to the electrode assembly. The electrode assembly serves as an amounting member for mounting all of the plurality or head modules thereon, and includes a conductive electrode plate formed with windows corresponding to the plurality of head modules. The head module includes a corresponding nozzle plate formed with the plurality of nozzles defining a nozzle row. The conductive electrode plate is in intimate contact with the nozzle plate. The nozzle row extends following one edge of the corresponding window. The purging means is in intimate contact with a side of the electrode plate that is opposite from a side of the electrode plate to which the nozzle plate is attached so as to block off the windows.
Moreover, there is also provided with a recording head including a plurality of head modules each formed with a plurality of nozzles for selectively ejecting an ink droplet and a mounting means for mounting the plurality of head modules. The mounting means is formed with a plurality of windows for the plurality of head modules. Portions of the mounting means defining edges of the windows serve as charging/deflecting electrodes for deflecting the elected ink droplet.